GB475585A - Improvements in or relating to valve parts and method of constructing the same - Google Patents

Abstract

475,585. Coating valves and valve seats with metals; alloys. WILCOXRICH CORPORATION. May 25, 1936, No. 14754. Convention date, June 3, 1935. [Classes 82 (i) and 82 (ii)] [Also in Groups XXII and XXVII] Valves and valve seats, particularly for internal-combustion engines, are coated on their co-operating faces with an alloy which will resist oxidizing, burning and pitting at high temperatures. The coating is applied, after the part has been cleaned and preferably preheated for example in a molten flux bath of borax or cryolite, by immersing the portion to be coated in a bath of the molten alloy and rotating the part. To increase the thickness of the coating adjacent the line of contact between the valve and the valve seat projections or grooves may be formed on or in the part, as shown at a in Figs. 4 and 7, for a valve and in Fig. 10 for a valve seat ring. The coated portion is afterwards worked to form a face which may be flat or sloping at any desired angle, various forms of faces being shown in the drawings. The thickness of the coating applied may be varied by varying the speed of rotation or the temperature of the bath ; a thick coating may be formed by several immersions. A coating of another metal such as aluminium, bronze, brass, or copper may be first applied by spraying, dipping, plating &c. to provide a clean surface to which the coating alloy will bond. The coating alloy may be that known under the Registered Trade Mark " Stellite " and the composition of other alloys which may be used is specified, one group of these alloys containing iron, carbon, silicon, chromium, and manganese and one or more of the elements molybdenum, tungsten, boron, nickel, and cobalt; and the other group being aluminium bronzes containing copper, aluminium and iron, and either manganese, or nickel, or chromium and cobalt.